The crash of Asiana Airlines Flight 214 in San Francisco on Saturday highlights how improvements in aviation safety have made it more likely that passengers will survive a crash. The major improvements made since the 1980s include:

Stronger seats

Today’s airplane seats - and the bolts holding them into the floor - are designed to withstand forces up to 16 times that of gravity. That prevents rows of seats from pancaking together during a crash, crushing passengers.

Fire-retardant materials

Carpeting and seat cushions are now made of materials that burn slower, spread flames slower and don’t give off noxious and dangerous gases.

Improved exits

Doors on planes are much simpler to open and easily swing out of the way, allowing passengers to quickly exit in an emergency. And planes now come with rows of lights on the floor that change from white to red when an exit is reached.

Better training

Flight attendants at many airlines now train in full-size models of planes that fill with smoke during crash simulations.

Stronger planes

Aircraft engineers have looked at structural weaknesses from past crashes and reinforced those sections of the plane.